The well-known correlation between global radio continuum
(RC) and far-infrared (FIR) emissions in external galaxies
is at the same time one of the most robust and one of the
most puzzling relations in extragalactic astronomy. The
RC/FIR correlation is linear and has a dispersion of only a
factor of two, over a luminosity range of more than four
orders of magnitude (e.g. Condon 1992, ARAA, 30, 576; Yun,
Reddy, & Condon 2001, 554, 803). The RC/FIR relation
appears to hold within galaxies down to size scales of about
100 pc, but breaks down on smaller scales (B. Wells, PhD
thesis). Even though the RC and FIR are both thought
ultimately to originate as a result of star formation in
molecular clouds, the tightness of the correlation is
surprising given the many disparate steps involved in
producing the two types of emission: the FIR is generally
believed to originate from warm dust that is heated by the
radiation from hot young stars, and the RC originates as
synchrotron emission from relativistic electrons accelerated
by supernova remnants. In this paper, we explore the
molecular cloud links to the FIR and RC in about a dozen
sources by using the new, 6"-resolution CO data from the
BIMA Survey of Nearby Galaxies (SONG). We also examine these
correlations on global scales for two dozen galaxies.
Preliminary results show that within some sources, the CO
and RC emissions are linearly correlated to within the
errors in the flux density measurements. Within other
galaxies, the small-scale correlation may be somewhat less
precise, at least on size scales as small as a few hundred
parsecs.